In this study, differences were analysed between two groups of online teachers in a Master of Special Educational Needs program. One group scored high on student satisfaction and the second group received low student satisfaction ratings. Findings indicate that high satisfaction is associated with relatively long and pedagogically complex messages that are most often addressed to the whole group. These messages are characterised by careful listening to the students, elaborate on content knowledge, and show online personality and social behaviour. The research resulted in preliminary guidelines for crafting asynchronous teacher messages that positively affect student satisfaction and a scoring guideline that can be used to score the quality of online teaching as expressed in online asynchronous messages.